Holding End Mills?

epanzella

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Got a new mill drill and I need tooling. I've been scouring the internet on the subject an every time some one has me convinced to us ER32 collets some one else comes along and makes a case for individual R8 end mill holders. As it's a round column machine ER32's would be more convenient but milling performance trumps convenience. What do you guys use and why?
 
end mill holders are a good deal smaller in diameter than ER32, sometimes lets you sneak in closer to features on the workpiece that the collet nut may run into.
 
I have R8 with collets & end I'll holders, went with Er32 cheapooes and that is all I got was a set up that does not run true. Seems to be the Er32 collets more than the holder. Got one usa made holder and collets still not running true. FOR ME THAT IS.
 
I use both, but I go out of my way to use R8 end mill holders whenever possible. Even if it means grinding a reduced shank on a x/32" or x/16" end mill down to the nearest x/8" size. Reason being is end mill holders are more rigid. It is probably my own imagination or ignorance, but when considering side loads on collets I visualize a system with some innate room for deflection. Most say that's a non-issue. Collets are more convenient and faster to use. Collets seat better with an aftermarket bearing nut, so you should grab one or two for $15/ea while you're at it.
 
I use Tormach's TTS system in my Tormach CNC and my mill/drill. The advantage is my tooling is all set up prior to machining and I can change tooling by changing the TTS ER20 tool holder with tool. Release of the tool holder usually is accomplish by loosening the drawbar and the holder pops free. No need to tap the drawbar. This requires multiple tool holders but my tool offsets are all preset so tool changes are quick and east. A similar thing can be done with R8 end mill holders but the tool height depends upon the amount of torque applied to the drawbar.

I also have a full set of R8 collets and R8 end mill holders for various diameters. The R8 end mill holders provide a more rigid tool mounting and they are less prone to pullout during aggressive milling when using end mills with Weldon shanks. I also use them for larger end mills.
 
Back to the OP's question. Which is better, an R8 collet/end mill holder, or an R8 adapter with an ER32 holder on the end, and then an ER32 collet?

Cut the middle man out, and stay with the R8. You can get quality used R8 holders for less then a set of chinesium ER32 collets, and the holder/adapter.

The little difference in length is not a big deal, If you have the room to slide the end mill out of the holder, it is only a little more to change out the holder. I try to stay with the same diameter shaft tooling, so you just need to loosen the draw bar, give it a slight tap, and swap the tooling.
 
Your Mill/Drill will handle both R8 and ER32 (or ER40) R8 collet holder.
a) you may have less runout with straight use of R8 collet as holder (one tolerance error)
b) if you are not looking for great precision, the ER32/40 holder will work just fine.
c) the ER32/40 holder will take up 2-odd inches of space between the bed and nose of the mill

I started with ER40 R8 holder and am migrating towards R8 holders.
 
Just to be clear here, when speaking of R8's we're talking about R8 end mill holders as opposed to R8 collets, right?
 
I am a newbie. Here is my take. I went with ER32 collets for my mill/drill for two main reasons. First I can use them on my lathe with an ER32/MT2 adapter for the tailstock and headstock and I made an ER32 chuck also. So one set of tool holders works on both the lathe and mill/drill. Second is ease of use. It is a PITA for me to have to loosen the drawbar to change tooling. I can't easily reach the drawbar. I have to stand on a stool to loosen the drawbar. By the time I get the stool, loosen the drawbar, change the tooling and re-tighten everything, and then move the stool out of the way I have spent way more time then what it takes with my ER32 collets. So ease of use and the ability to use on the lathe and the mill/drill trumped any extra precision I might have gotten from R8 collects. Cost was a factor too but not the deciding factor.
 
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